Search

The aim of this study was to determine the physical and physiological demands of intercounty camogie match-play between positions and halves of play. Data were collected from 28 players during 18 competitive games using global positioning systems (10-Hz) and heart rate monitors (2.4-GHz). The study demonstrated that intercounty camogie players covered a total distance (TD) (m ± SD) of 6,040 ± 628 m, relative distance (RD) of 83 ± 13 m⋅min-1, and maximum speed of 25 ± 1 km⋅h-1. Furthermore, the players covered a mean sprint distance of 214 ± 112 m and 14 ± 6 sprints. Players' mean heart rate (HRmean) and HRmaxwas 138 ± 23 b⋅min-1 and 164 ± 20 b⋅min-1, respectively. There were decrements between halves in TD (p < 0.01, ES = -0.45), RD (p < 0.01, ES = -0.45), maximum speed (p < 0.05, ES 5 -0.18), HRmax(p < 0.05, ES = -0.23), running (p < 0.01, ES = -0.34), high-speed running (p < 0.01, ES = 0.34), sprinting (p < 0.01, ES 5 -0.10), HRmax(p < 0.05, ES = -0.23), and HRmax % (p < 0.05, ES = -0.24). Midfielders covered a greater TD compared with full-forwards (p < 0.05, ES 5 -0.38) and half-forwards (p < 0.05, ES 5 -0.38). Full-backs covered a significantly lower RD than midfielders (p < 0.05, ES 5 -1.2), half-backs compared with full-forwards (p < 0.05, ES 5 1.14), and half-forwards compared with full-forwards (p < 0.05, ES 5 1.15). Full-forwards covered significantly less RD when compared with half-backs (p < 0.05, ES 5 -1.14), midfielders (p < 0.05, ES 5 -1.47), and half-forwards (p < 0.05, ES 5 -1.15). The findings provide physical and physiological values on the match demands of intercounty camogie match-play. [ABSTRACT FROM AUTHOR]

Relationships between force-generating capabilities and weightlifting performance (e.g., snatch, clean and jerk [C&J], and combined total) have previously been explored in adult weightlifters; however, associations in young athletes are unknown. The purpose of this study was twofold: (a) to examine the relationships between countermovement jump (CMJ) and isometric midthigh pull (IMTP) kinetics and weightlifting performance in young weightlifters and (b) to determine the proportion of weightlifting performance that could be accounted for by CMJ and IMTP kinetics using principal component analysis (PCA). Thirty-seven young weightlifters (12-18 years of age) completed 3 trials of CMJ and 2 trials of the IMTP assessments on dual force plates. Recent competition maximum loads, obtained within 2 weeks of the data collection, for the C&J and snatch were also recorded. Pearson's zero-order correlation coefficients demonstrated moderate to very high correlations (r = 0.359-0.801; all p ≤ Benjamini-Hochberg critical values [B-Hα]) between CMJ kinetic variables, including jump height, average braking force, average braking velocity, absolute and relative braking net impulse, absolute and relative force at minimum displacement, absolute and relative propulsive force, absolute and relative propulsive net impulse and average propulsive velocity, and weightlifting performance. High to very high correlations were evident between IMTP peak force and relative peak force and all weightlifting performance metrics (snatch, C&J, combined total, combined total [kg]/body mass [kg-0.67], and Sinclair's total; r = 0.538-0.796; p ≤ B-Hα). Components from the PCA were used to conduct stepwise, multiple, linear regression analyses. Moderate (45.8-52.9%) and large percentages (79.1-81.3%) of variance in absolute measures of weightlifting performance were explained by IMTP peak force variables and CMJ propulsive variables, respectively. These novel findings indicate that IMTP peak force variables and CMJ propulsive variables could provide valuable insight for talent identification and long-term athletic development in junior weightlifting pathways. [ABSTRACT FROM AUTHOR]

ntroduction: Despite increases in research and implementation, physical literacy continues to be largely misinterpreted by practitioners. The purpose of this study was to devise, implement, and evaluate a professional development program that works in a primary school environment to enhance their knowledge and operationalization of physical literacy. Methods: Following a 3-month needs assessment phase, data were collected from structured observations, reflections, and semistructured interviews with the teachers, before, during, and after an introductory workshop and 6-month physical literacy intervention. Thematic analysis was used to evaluate perceptions of program effectiveness. Results: The needs assessment phase identified notable differences between teachers' classroom and physical education practice. Results of the physical literacy workshop and intervention detailed an increase in teachers' knowledge of, and operationalization of, physical literacy. Discussion/Conclusions: Applying established principles of effective professional development in a contextually sensitive manner was viewed as effective in enhancing primary school teachers' knowledge and practice regarding physical literacy.

Questions continue to be raised about the validity that is in existence to estimate Db, in professional male footballer players. Phase 1: n = 28 anthropometric variables were used on n = 206 footballers, using regression analyses to determine standard error of estimate and R2. A cut-off correlation coefficient set at r = 0.950 and 90% R2. Phase 2: all variables (z-scores, $$\bar x$$ x ˉ = 0.0, SD = ±1.0) to help reduce heteroscedasticity, β, r, t, significance of t and P-values were calculated. Phase 3: a forced stepwise–backwards regression analysis approach with nine predictors which met the acceptance criteria (r = 0.950, R2 = 90% and β weights) was used to develop a 'best fit' and a 'practical' calibration model. Phase 4: cross-validation of the two newly developed calibration method using LoA. The 'best fit' model SEM (0.115 g ml−1), the highest R2 (6.6%) (P ≤ 0.005), whereas the 'practical' calibration model SEM (0.115 g ml−1), R2 (4.7%) (P ≤ 0.005) with r values = 0.271 and 0.596 and R2 (%) coefficients = 0.3526 for the 'best fit' and 'practical' calibration models, respectively (P = 0.01). The two calibration models supported an ecologically and statistically valid contribution and can provide sound judgements about professional footballers' body composition. [ABSTRACT FROM AUTHOR]

This study examined the dietary habits of Welsh 12-13 year olds. A cohort of 84 boys and 81 girls, age 12.9 SD 0.3 years; body mass 51.3 SD 12.6kg; and stature 1.54 SD 0.08m, completed a food frequency questionnaire and seven-day food diary. Mean daily kilocalories (kcal/d), and percentages of total fat, saturated fat, carbohydrate, and protein, as well as fibre intake were calculated. The mean daily intake of total fat for this cohort was 34.7 percent, for saturated fat the value was 13.8 percent. The mean daily intake of carbohydrate and protein were 50.5 and 14.9 percent, respectively. The schoolchildren in this study reported a mean daily fibre intake of 12.3g. The absolute intake of kilocalories was significantly greater (p [less than or equal to] 0.05) among boys than girls, but no other significant differences were reported. This study revealed that the diets of Welsh 12-13 year olds exceeded recommendations for fat, while at the same time did not meet the recommendations for fibre, and particularly fruit and vegetable intake. Our data indicated that, despite schools offering a range of healthy lunchtime foods, young people continue to consume an energy-dense and nutrient-poor diet, both at school and at home. (Contains 3 tables.)

Objective: This study considers the physical activity (PA) and dietary habits of British young people according to socio-economic status (SES). Methods: The PA and dietary habits of 98 boys and 101 girls (12.9 0.3 years) from two Welsh secondary schools (school 1 and school 2) were examined. Free school meal eligibility and Census 2001 data were used as indicators of SES. School 1 was designated high SES, while school 2 represented low SES. Participants were classified according to SES. Physical activity was estimated by seven-day recall and questionnaire; dietary patterns were assessed using a seven-day food diary and questionnaire. Results: Two-thirds of all participants had not taken part in vigorous activity over the last week. Furthermore, 83.8 per cent of participants did not meet the Health Education Authority's recommendation of one hour per day moderate activity. Boys were more active than girls, (P less than or equal 0.05), but SES did not influence time spent in activity. Ninety-four percent of participants were taken to school via motorized transport. There were no significant differences in fat intake between the sexes or across SES. In addition, 93 per cent of the participants, irrespective of SES, exceeded the 10 per cent saturated fat cut off point recommended by the World Health Organization. Conclusion: Physical activity and dietary patterns are modifiable through suitable lifestyle changes. The present data support the notion that preventative strategies for combating chronic diseases should begin early in life and across socio-economic statuses. (Contains 4 tables.)

This study determined the prevalence of coronary heart disease (CHD) risk factors in young people of differing socio-economic status (SES). A cohort of 100 boys and 108 girls, aged 12.9, SD 0.3 years drawn of differing SES were assessed for CHD risk factors. Measurements included indices of obesity, blood pressure, aerobic fitness, diet, blood lipids and lipoproteins. Significant differences (P [less than or equal to] 0.05) were detected with respect to SES, for systolic blood pressure, total cholesterol and low density lipoprotein cholesterol, but in boys only. Significant sex differences (P [less than or equal to] 0.05) were identified for systolic blood pressure, diastolic blood pressure, aerobic fitness, waist to hip ratio, summation of four skinfold thicknesses, average daily kilocalorie intake, total cholesterol and low density lipoprotein cholesterol. Moreover, increased body fatness, low aerobic fitness, a high fat diet and elevated lipoprotein (a), were the most frequently identified CHD risk factors in this cohort. This study reveals a high incidence of CHD risk factors in young people irrespective of SES and sex, and highlights the need for vigilance in identifying such risk factors from a young age. (Contains 4 tables and 1 note.)

Purpose: To understand how training periodization influences sprint performance and key step characteristics over an extended training period in an elite sprint training group. Methods: Four sprinters were studied during 5 mo of training. Step velocities, step lengths, and step frequencies were measured from video of the maximum velocity phase of training sprints. Bootstrapped mean values were calculated for each athlete for each session, and 139 within-athlete, between-sessions comparisons were made with a repeated-measures analysis of variance. Results: As training progressed, a link in the changes in velocity and step frequency was maintained. There were 71 between-sessions comparisons with a change in step velocity yielding at least a large effect size (>1.2), of which 73% had a correspondingly large change in step frequency in the same direction. Within-athlete mean session step length remained relatively constant throughout. Reductions in step velocity and frequency occurred during training phases of high-volume lifting and running, with subsequent increases in step velocity and frequency happening during phases of low-volume lifting and high-intensity sprint work. Conclusions: The importance of step frequency over step length to the changes in performance within a training year was clearly evident for the sprinters studied. Understanding the magnitudes and timings of these changes in relation to the training program is important for coaches and athletes. The underpinning neuromuscular mechanisms require further investigation but are likely explained by an increase in force-producing capability followed by an increase in the ability to produce that force rapidly. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether wearing lower-body compression garments attenuate indices of muscle damage and decrements in performance following drop-jump training. Seven trained female and four trained male subjects undertook blood collection for creatine kinase (CK) and lactate dehydrogenase (LDH), a mid-thigh girth measurement, and reported their perceived muscle soreness (PMS). A series of performance tests were then completed including sprints (5 m, 10 m, and 20 m), a 5-0-5 agility test, and a countermovement jump test. In a randomized crossover experimental design, separated by 1 week, subjects completed 5 x 20 maximal drop-jumps, followed immediately after exercise by either wearing graduated compression tights (CG) or undertook passive recovery as a control (CON) for 48 hours. CK, LDH, mid-thigh girth, and PMS were retested after 24 hours and 48 hours of recovery. The performance tests were repeated after 48 hours of recovery. Analysis of variance for repeated measures indicated that for female subjects, OK values were elevated after 24-hour recovery (p = 0.020) and a greater PMS was observed after 48-hour recovery in the CON condition (p = 0.002) but not for the CG condition. For all the subjects (n = 11), a greater PMS was observed after 48-hour recovery in the CON condition (p = 0.001) but not the CG condition. Significant increases in time were reported for 10-m (p = 0.016, 0.004) and 20-m sprints (p = 0.004, 0.001 ) in both the CON and CG conditions and for the 5m sprint (p = 0.014) in the CG condition. All other parameters were unchanged in either condition. Data indicates that CK responses and PMS might be attenuated by wearing compression tights in some participants after drop-jump training; however, no benefit in performance was observed. KEY WORDS muscle damage, creatine kinase, lactate de hydrogenase, performance

Byrne, PJ, Moody, JA, Cooper, S-M, Farrell, E, and Kinsella, S. Short-term effects of "composite training" on strength, jump, and sprint performance in hurling players. J Strength Cond Res 36(8): 2253–2261, 2022—The purpose of this study was to compare the short-term effects of "composite" training to sprint training on strength, jump, and sprint acceleration performance in hurling players. A randomized counterbalanced group design with baseline test, pretest and post-test measures was used. Twenty-five hurling players volunteered to participate and 21 completed the study. Subjects were divided into a "composite" (COMP group, n = 10) or a sprint training (SPRINT group, n = 11) group. Both groups trained twice per week for 7 weeks with the SPRINT group performing 6 repetitions of 20 m sprints and the COMP group completing 6 repetitions (1 repetition = 3 bounce drop jumps [BDJs] with a 20 m sprint after 15 seconds recovery). Significant differences existed pretraining to post-training for the COMP group for BDJ contact time (−7.25%; p = 0.05) and countermovement jump (CMJ) variables (height: 7.43%, p = 0.006; force: 5.24%, p = 0.05; power: 15.11%, p = 0.001). No significant differences were found between groups at baseline and for group by time interactions. Significant improvements were observed pretraining to post-training in both groups for the following: absolute 3 repetition maximum (3RM) back squat strength (12.73–17.62%, p = 0.01), 5 m (5.74–9.49%, p = 0.006–0.04), 10 m (4.27–5.59%, p = 0.007–0.02), and 20 m (3.35–3.98%, p = 0.003–0.01). In conclusion, "composite" training is effective in enhancing fast stretch-shortening cycle efficiency inducing CMJ force and power augmentation. However, "composite" and sprint training are effective training approaches for enhancing maximal strength and sprint performance in a time efficient manner in hurling players. [ABSTRACT FROM AUTHOR]

A study assessing the prevalence of the identified coronary heart disease risk factors in children and adolescents of differing socioeconomic status is carried out. Results conclude that elevated fibrogen, homocyst(e)ine, and C-reactive protein are present in this cohort of British children and although some social variation in the identified CHD risk factors in young people exists, the evidence is weak but differences might become more apparent in later life as environmental factors become more influential.

During pregnancy, assessment of cardiac output (1), a fundamental measure of cardiovascular function, provides important insight into maternal adaptation. However, methods for dynamic measurement require validation. The purpose of this study was to estimate the agreement of measured by echocardiography and Modelflow® at rest and during submaximal exercise in non-pregnant (n = 18), pregnant (n = 15, 22-26 weeks gestation) and postpartum women (n = 12, 12-16 weeks post-delivery). Simultaneous measurements of derived from echocardiography [criterion] and Modelflow® were obtained at rest and during lowmoderate intensity (25% and 50% peak power output) cycling exercise and compared using Bland-Altman analysis and limits of agreement. Agreement between echocardiography and Modelflow® was poor in nonpregnant, pregnant and postpartum women at rest (mean difference ± SD: -1.1 ± 3.4; -1.2 ± 2.9; -1.9 ± 3.2 L.min-1), and this remained evident during exercise. The Modelflow® method is not recommended for determination in research involving young, healthy non-pregnant and pregnant women at rest or during dynamic challenge. Previously published data from studies utilising this method should be interpreted with caution. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine relationships between aerobic fitness (AF), fatness, and coronary-heart-disease (CHD) risk factors in 12- to 13-year-olds. The data were obtained from 208 schoolchildren (100 boys; 108 girls) ages 12.9 ± 0.3 years. Measurements included AF, indices of obesity, blood pressure, blood lipids and lipoproteins, fibrinogen, homocysteine, and C-reactive protein. An inverse relationship was found between AF and fatness (p = .05). Fatness was related to a greater number of CHD risk factors than fitness was (p = .05). Further analysis revealed fatness to be an independent predictor of triglyceride and blood-pressure levels (p = .05). Our findings indicate that, for young people, fatness rather than fitness is independently related to CHD risk factors. [ABSTRACT FROM AUTHOR]

Key points: We sought to determine the isolated and combined influence of hypovolaemia and hypoxic pulmonary vasoconstriction on the decrease in left ventricular (LV) function and maximal exercise capacity observed under hypobaric hypoxia.We performed echocardiography and maximal exercise tests at sea level (344 m), and following 5–10 days at the Barcroft Laboratory (3800 m; White Mountain, California) with and without (i) plasma volume expansion to sea level values and (ii) administration of the pulmonary vasodilatator sildenafil in a double‐blinded and placebo‐controlled trial.The high altitude‐induced reduction in LV filling and ejection was abolished by plasma volume expansion but to a lesser extent by sildenafil administration; however, neither intervention had a positive effect on maximal exercise capacity.Both hypovolaemia and hypoxic pulmonary vasoconstriction play a role in the reduction of LV filling at 3800 m, but the increase in LV filling does not influence exercise capacity at this moderate altitude. We aimed to determine the isolated and combined contribution of hypovolaemia and hypoxic pulmonary vasoconstriction in limiting left ventricular (LV) function and exercise capacity under chronic hypoxaemia at high altitude. In a double‐blinded, randomised and placebo‐controlled design, 12 healthy participants underwent echocardiography at rest and during submaximal exercise before completing a maximal test to exhaustion at sea level (SL; 344 m) and after 5–10 days at 3800 m. Plasma volume was normalised to SL values, and hypoxic pulmonary vasoconstriction was reversed by administration of sildenafil (50 mg) to create four unique experimental conditions that were compared with SL values: high altitude (HA), Plasma Volume Expansion (HA‐PVX), Sildenafil (HA‐SIL) and Plasma Volume Expansion with Sildenafil (HA‐PVX‐SIL). High altitude exposure reduced plasma volume by 11% (P < 0.01) and increased pulmonary artery systolic pressure (19.6 ± 4.3 vs. 26.0 ± 5.4, P < 0.001); these differences were abolished by PVX and SIL respectively. LV end‐diastolic volume (EDV) and stroke volume (SV) were decreased upon ascent to high altitude, but were comparable to sea level in the HA‐PVX trial. LV EDV and SV were also elevated in the HA‐SIL and HA‐PVX‐SIL trials compared to HA, but to a lesser extent. Neither PVX nor SIL had a significant effect on the LV EDV and SV response to exercise, or the maximal oxygen consumption or peak power output. In summary, at 3800 m both hypovolaemia and hypoxic pulmonary vasoconstriction contribute to the decrease in LV filling, but restoring LV filling does not confer an improvement in maximal exercise performance. Key points: We sought to determine the isolated and combined influence of hypovolaemia and hypoxic pulmonary vasoconstriction on the decrease in left ventricular (LV) function and maximal exercise capacity observed under hypobaric hypoxia.We performed echocardiography and maximal exercise tests at sea level (344 m), and following 5–10 days at the Barcroft Laboratory (3800 m; White Mountain, California) with and without (i) plasma volume expansion to sea level values and (ii) administration of the pulmonary vasodilatator sildenafil in a double‐blinded and placebo‐controlled trial.The high altitude‐induced reduction in LV filling and ejection was abolished by plasma volume expansion but to a lesser extent by sildenafil administration; however, neither intervention had a positive effect on maximal exercise capacity.Both hypovolaemia and hypoxic pulmonary vasoconstriction play a role in the reduction of LV filling at 3800 m, but the increase in LV filling does not influence exercise capacity at this moderate altitude. [ABSTRACT FROM AUTHOR]